Tooth and gum disease can lead to serious health problems in companion animals. Dogs and cats tend to significantly use their teeth when chewing on foodstuffs. Therefore, gum disease and loss of teeth can all have serious consequences for companion animals. Damage to the teeth and gums in companion animals is considered to be permanent. According to the American Veterinary Dental Society, 80% of dogs and 70% of cats have periodontal (gum) disease by the age of three. Proper dental care could increase the life of these animals by many years. Within that context, maintenance of good oral health and prevention of oral disease is a primary necessity for animals. However, pet owners have to provide that necessity.
Dog teeth and gums are also susceptible to many of the same oral health problems as humans. This includes plaque buildup, dental tartar (calculus), gingivitis and various periodontal diseases. The survival of pathogenic bacteria in the oral cavity depends on their successful adhesion to dental surfaces and their ability to develop into biofilms, known as dental plaque. This can eventually solidify into tartar (calculus) on the teeth. Bacteria from the dental plaque are responsible for the development of dental caries, gingivitis, periodontitis, stomatitis and peri-implantitis. The mouth environment is rich in bacterial flora which in some conditions may lead to such diseases like caries or diseases of periodontium or even halitosis. The basic role in development of dental caries plays Streptococcus mutans and, to a lower degree, Lactobacillus sp. Cariogenic influence of other bacteria including Streptococcus, Enterococcus, or Actinomyces is well known. Virulence of Streptococcus mutans results from its adhesion, acid-forming properties, and tolerance to environment with low pH.
Bacterial flora of the mouth can cause not only caries but also periodontal disease. Bacterial plaque accumulated over and under gums contributes to inflammation of the tissues adjacent to teeth which leads to clinical attachment loss and a loss of alveolar process. Microbes which are located in the subgingival plaque are divided into five complexes. One of them, the “red complex” made up of Tannerella forsythensis, Porphyromonas gingivalis, and Treponema denticola, has strong relation with an increased depth of periodontal pockets and with a bleeding on probing. Prevotella intermedia and Fusobacterium nucleatum are also main microbiota involved in periodontal disease related to plaque. A decrease of the number of these pathogenic microbes could potentially influence epidemiology of periodontal diseases by a limitation of their number and intensity.
The first stage of periodontal disease is gingivitis, which is very common. In this stage, the bacteria have mixed with saliva and formed plaque. Plaque adheres to the teeth and hardens, forming tartar and calculus. These tartar deposits irritate the gum tissue and cause inflammation, swelling, and infection. It is at this stage that gingivitis is most notable. It is important to the overall health of the dog that proper dental care is provided before bacteria and/or their toxins to enter the bloodstream with potentially deleterious effects on various internal organs. Conversely, poor systemic health may manifest in the oral cavity in various ways and may also exacerbate periodontal disease.
While bacteria have traditionally been the focus of oral diseases, viruses play a significant role in these diseases as well (Grindel). The role of several viruses in ulceration is well known, but viruses of the herpes family may play a role in periodontitis, and papillomaviruses are probably involved in oral cancer. Anti-herpes medication may, in some cases, be relevant in treating periodontitis, while papillomavirus vaccine would be expected to decrease the prevalence of oral cancer.
With many of the oral diseases, there is little recourse available to the pet owner. If an oral disease is diagnosed early enough, aggressive and regular oral cleaning may eventually clear up the problem. A veterinarian and/or pet owner may have to clean the pet's oral cavity several times a week for months or for the duration of the animal's life. This is typically done by brushing or scraping the teeth and gums and may require a sedated animal in order to not get bitten. The brushing option requires considerable input in time, effort or money from the pet owner.
Attempts to prevent dental diseases in companion animals through the use of hard chews has been a partial answer for pet owners who do not wish to get bitten when cleaning the teeth of an animal. Chewing is very important for dog's oral health. It keeps the dog's teeth clean through physical scraping of a harden matrix against the teeth to remove plaque and tartar buildup. It is a natural behavior of dogs to chew on a variety of objects that allows for hard substances including natural and artificial matrixes to be used to help remove plaque.
In the last 20 years, digestible hard chews made out of starch or grains became available that have some nutritional value by providing vitamins, minerals and other certain botanical extracts that may help with keeping the breath of the animal fresh. The trend is towards chews that can have some nutritional value besides the traditional use of keeping teeth clean and satisfying the urge to chew by dogs. The annual total hard chew market in the USA is around $500,000,000. As the trend is towards digestible chews, having the ability to incorporate plaque reducing actives into a digestible hard chew represents advancement in the field and will be a competitive advantage. However, the hard chews on the market do not contain plaque reducing actives.
Dog hard chews come in a variety of materials and are generally used as a method to keep the dog's teeth clean while satisfying the normal ongoing chewing behavior associated with dogs. Dog chews fall into 3 general categories based on their composition. They can be made from animal, plant or from artificial ingredients. Examples of chews being made of animal-derived parts or ingredients include bull penis, cheese, deer antler, fish skin, rawhide, pig ears, cow hooves and real bones. Plant-based chews can be based on various plant starches, dried yam, and sweet potato. Artificial ingredients for creating chews can include rubber, nylon and thermoplastics. The hard chews made out of plastic-like materials can last for months; however, these are not digestible. The hard chews made out of animal or plant materials are digestible. This digestible hard chew will typically last perhaps through 30 minutes of chewing and can help keep teeth clean while providing vitamins and minerals to the animal.
However, the concept of a digestible hard chew of any composition category as an option to improve health of the dog would be greatly improved if antimicrobial agents that reduce plaque in an active manner were incorporated into the digestible hard chew format. This would allow the dog to not only get benefits of teeth cleaning and satisfying normal chewing behavior but also reduce plaque through active killing mechanisms of bacteria rather than physical removal mechanisms.
While hard chew formats have been used in attempts to help maintain oral health in companion animals, they can be improved by the addition of antimicrobial actives. Therefore, there is a need for hard chew compositions for maintaining good oral health as well as preventing and treating oral disease in companion animals by the addition of plaque removing ingredients.